Apparatus for final folding

ABSTRACT

An apparatus for the inward or final folding of end portions of a covering on a panel (5). The covering (1) surrounds the panel (5) and extends out over one edge to such an extent that at least first inward folds (17, 18) overlap one another from two opposite edges. Second inward folds (16) from the two opposing edges are located inside the overlapping, first inward folds (17, 18). A corner support (21) is placeable in the corner for folding of the second inward fold (16) about the corner support (21), with the aid of a stirrup (38) which is switchable for inward folding of the second inward fold (16) about the corner support (21) while leaving exposed an adhesive application surface on the second inward fold (16). A first folder (43) is provided for inward folding of one first inward fold (17), and a second folder (44) is provided for inward folding of another first inward fold (18) after application of adhesive to the adhesive application surface.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus for the final folding, orinward folding, of at least the end portion, in particular corners, of acovering on a panel, in which the covering surrounds the panel andprojects out over at least one edge to such an extent that at leastfirst inward folds from two opposing edges overlap one another, whilesecond inward folds from the opposite edges are located inside theoverlapping first inward folds.

At present, there is no suitable machine, apparatus or plant for thesubstantially automated covering of panels of, for example Gullfiber® orthe like for use of the finished product as acoustic absorbent indifferent environments. The covering is normally made of fibre-glassfabric or some other suitable material. Hitherto, substantially the onlysolution has been manual covering of Gullfiber® panels with fibre-glassfabric. It has proved to be particularly difficult to obtain, under suchcircumstances, smooth and straight corners and as uniform products aspossible. In many environments, extreme demands are placed on theappearance of the product. It is naturally also desirable in the art tobe able to devise a machine which requires few manual operations andwhich may be considered as almost fully automatic.

SUMMARY OF THE INVENTION

The object of the present invention is to satisfy the above-outlineddesiderata and needs.

Employing an apparatus according to the present invention, it has provedpossible to be able, almost wholly without manual operations, to coveror clad Gullfiber® panels with fibre-glass fabric for realizing acousticabsorbents of extremely high standards in respect of appearance. Thisimplies that the absorbents display substantially smooth and evensurfaces and smooth and even edges as well as straight corners. It has,moreover, proved to be difficult to reveal any discrepancies between thedifferent absorbents, their quality proving, instead, to be highlyuniform. Nor does there appear to be anything which prevents theapparatus according to the present invention from being applied in othercontexts in which it is desirable to achieve even and straight cornerson a covering of a relatively soft panel-shaped object.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described in greater detail hereinbelow,with particular reference to the accompanying Drawings. FIG. 1 shows adiagram of a plant for utilizing the present invention. FIG. 2 is a sideelevation of a fabric application table. FIG. 3 shows a side elevationsimilar to that of FIG. 1 of another embodiment of the applicationtable. FIG. 4 is a schematic partial view of an apparatus for the inwardfolding of the covering on one longitudinal edge of a panel. FIG. 5 is aschematic view of a corner support in the starting position. FIG. 6 is aview similar to that of FIG. 5 of the corner support on its way down ina corner. FIG. 7 is a view similar to that of FIG. 5 with the cornersupport in position in a corner. FIG. 8 is a view similar to that ofFIG. 5 with the corner support on its way up out of the corner. FIG. 9shows a view of a portion of an apparatus according to the presentinvention which is disposed at a corner. FIG. 10 shows a view, partly inperspective, of the corner portion according to the present invention,as illustrated in FIG. 9, but with the parts in starting position. FIG.11 shows a view similar to that of FIG. 10 with the parts in the cuttingphase. FIG. 12 Shows a view similar to that of FIG. 10 with the cornersupport in the fold-supporting position. FIG. 13 is a view similar tothat of FIG. 12, the needle support being in the needle-supportingposition. FIG. 14 is a view similar to that of FIG. 10, the stirruphaving been switched to the corner flap infold position. FIG. 15 is aview similar to that of FIG. 14, a glue strand having been applied tothe corner flap and the one edge flap or edge infold. FIG. 16 is a viewsimilar to that of FIG. 15, the upper edge flap or edge infold havingbeen folded in. FIG. 17 is a view similar to that of FIG. 16, the lowerinfolder having been pivoted to the infold position, while the upperinfolder has been returned to its starting position. FIG. 18 shows aview similar to that of FIG. 17, the corner support and the stirruphaving been returned to their starting position. FIG. 19 is a top planview of an apparatus with four corner modules of the type illustrated inFIGS. 9-18 for simultaneous handling of all four corners of a partlycovered panel.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

The embodiment shown on the Drawings of an apparatus according to thepresent invention is intended for covering or cladding of so-calledGullfiber® panels of dimensions of, for example, 1 200×600×50 mm.Naturally, the Gullfiber® panels may also consist of other similar fiberpanels, for example mineral wool. Naturally, there is nothing to preventpanels or plates of other dimensions from being clad or coveredaccording to the present invention. In the present embodiment, thecovering or cladding consists of a fibre-glass fabric of substantiallythe same type as is employed for walls and the like. As illustrated inFIG. 1, the fibre-glass fabric is provided in the form of a roll 1 fromwhich the fibre-glass fabric is drawn out across a table 2 past acutting machine 3 and beneath a magazine 4 for a number of uprightplates or panels 5. After cutting of the fibre-glass fabric by means ofthe cutting machine 3 in a suitable length for enclosing a panel 5, thepanel 5 is pressed, together with the fibre-glass fabric, through anopening 6 in the table 2 as illustrated more clearly in FIGS. 2 and 3.The fibre-glass fabric 1 will form an edge 7 and an edge 8 on eitherside of one longitudinal edge of the panel 5. See FIG. 4. The onefibre-glass fabric edge 7 is folded in over the panel edge with the aidof a reciprocally displaceable folder 9. Either the fabric edge 7 or thefabric edge 8 is provided with a strand of a suitable adhesive, forexample a hot melt glue, whereafter the opposing edge 8 is folded inover the already folded-in fabric edge 7 by means of a pivotal folder10.

The fibre-glass fabric 1 is slightly wider than the length of the platesor panels 5 so that the fibre-glass fabric projects out over the ends ofthe plates or panels 5 substantially in the same way as the longitudinalfabric edges 7 and 8 in FIG. 4. In order that the fibre-glass fabric 1extend as uniformly and smoothly around the panel 5 as possible once thepanel 5 has been passed through the opening 6 together with thefibre-glass fabric 1, it is appropriate that the opening 6 proper in thetable top 2 be of slightly conical shape, as illustrated in FIG. 3.

After the gluing of the fibre-glass fabric 1 according to FIG. 4, thepanel 5 is transported via a table 11 to an end edge infold apparatus 12which may also be designated a corner folding apparatus. This isillustrated in the assembled state in FIG. 19, and FIGS. 5-18 illustrateparts thereof. According to FIG. 19, the apparatus is provided with acorner module for each corner of the panel 5. This corner module isshown in greater detail in FIG. 9, and parts thereof are shown ingreater detail in the other part detail drawings.

The accuracy tolerances in manufacture of the Gullfiber® panels 5 aresuch that their size may vary by ±5 mm in length and width. In orderthat the corners be sharp and straight, the apparatus 12 must,therefore, be adjustable to the actual size of the panel 5. In theapparatus illustrated in FIG. 12, this problem has been solved by meansof linear units which are adjusted with the aid of pneumatic cylindersafter sensing of the size of the panel with the aid of microswitches.Thus, two cylinders 13 and 14 are provided for width adaptation, andcylinders are also provided on the underside for length adaptation tothe panel. One corner module may be fixed, while the other three must bedisplaceable for adaptation to the relevant dimensions of the panel 5.Each corner module has upper and lower pneumatically driven shears 15.The shears 15 are available as complete units, for which reason they areonly illustrated schematically in FIG. 11. After cutting of thefibre-glass fabric 1 by the shears 15 in each corner, a corner flap 16is formed, as well as an upper flap 17 and a lower flap 18. The flaps16, 17 and 18 can naturally also be designated inward folds. Arrows areemployed, like the arrows 19 and 20 in FIG. 11, to illustrate themovement of the components in question in the different Figures, in thedirection of each arrow.

In order that the corner of the panel 5 covered with the fibre-glassfabric 1 be sharp and straight, it is appropriate to fold the flap 16about a support. In this embodiment of the present invention, thesupport consists of a needle 21 which is shown in greater detail inFIGS. 5-8 and is pivotally disposed in a shift block 22. The block 22is, in its turn, displaceable up and down along two rods 23 and 24 whichare secured in a bracket 25. Pneumatic cylinders are provided (notshown) for moving the block 22 along the rods 23 arid 24. On one side ofthe block 22, the needle 21 is bent for cooperation with an upper guidecam 26 and a lower guide cam 27, the upper guide cam pivoting the needle21 to substantially horizontal position according to FIGS. 5 and 6,while the lower guide cam 27 pivots the needle 21 to substantiallyvertical position in accordance with FIGS. 7 and 8. The position inFIGS. 7 and 8 can, of course, also be considered as at right angles tothe position shown in FIGS. 5 and 6. The pivoting of the needle 21 onlytakes place once the block 22 has reached the guide cam 27 and passedit, to the position illustrated in FIG. 7. Thus, the needle 21 is movedfrom the position illustrated in FIG. 11 to the position illustrated inFIG. 12. The needle 21 can be assumed to be quite flimsy and easilyflexible in the position shown in FIGS. 12 and 13, for which reasonthere is provided, on the underside of the panel 5, a support and guidepiece 28 (FIG. 10) which is disposed on a rod 29 which is guided in anangle bracket 30 and is interconnected to a pneumatic cylinder forswitching in the direction of the arrow. The piece 28 is provided with aV-shaped guide groove 31 for accurate positioning of the needle 21. Withthe aid of the piece 28 and the block 22, the needle 21 will thus, beheld in an accurately positioned location for defining a straight andalmost exactly placed corner support about which the flap 16 can befolded.

The corner flap 16 is folded with the aid of a corner plate 32 which isdisplaceable towards and away from the needle 21 under spring loading.The corner plate 32 is secured on the ends of two rods 33 and 34 (FIG.11) which are displaceable in a frame 35. Between the frame 35 and thecorner plate 32 compression springs 36 and 37 are disposed on the rods33 and 34 for returning to the starting position.

As is apparent in FIG. 14, the entire frame 35 is movable to and awayfrom the needle 21 for urging the corner plate 32 thereagainst andshifting a wire stirrup 38 into the corner and complete inward foldingof the corner flap 16 and urging the flap against the end of the panel5. The insertion of the frame 35 preferably takes place by means of apneumatic cylinder (not shown). The wire stirrup 38 is pivotal about itslower shank 39 by means of a pneumatic rotary cylinder (not shown)coupled to the lower shank 39 and mounted on a part 41 of the frame 35.With the parts in the position illustrated in FIG. 14, an adhesivestrand 42 is applied, as illustrated in FIG. 15 (the adhesive optionallyconsisting of a suitable hot melt glue). Adhesive strand 42 extendspartly on the corner flap 16 and partly on the lower flap 18. After theapplication of the glue strand 42, an upper folder 43 is displaceddownwardly over the flap 17 for folding thereof over the edge surface ofthe panel 5, whereafter the folder 44 is pivoted upwardly orcounterclockwise for inward folding of the flap 18 onto the upper flap17, whereby the upper flap 17 will partly be glued on the corner flap 16and the lower flap 18 will be glued partly on the corner flap 16 andpartly on the upper flap 17. By such means, there will be obtained adependable and efficient fixing of the different flaps on one another,whereby the form of the fold will be retained.

After the folding-in of the lower flap 18, the folder 43 is moved backto its upper position (FIG. 17), whereafter the wire stirrup 38 ispivoted from the position illustrated in FIG. 17 to the positionillustrated in FIG. 18 and the needle 21 is displaced upwardly to itsupper position, whereby both the wire stirrup 38 and the needle 21 willhave been extracted from the finished corner without having negativelyaffected the shape or configuration of the corner in any way whatever.

The above-mentioned phases are executed in each corner module, wherebyall corners can be finished at the same time. According to FIG. 9, eachcorner module is displaceable by means of a pneumatic cylinder 45 on arail 46, in which event the arm 47 carrying the shears 15 is thensectioned. The corner module shown in the upper left-hand corner of FIG.19 is, moreover, pivotal by means of a hinge 48. The moving parts shownin FIG. 19 are located in a position for a panel 5 with fabric 1 whichhas minimum dimensions and is urged outwardly by a panel of slightlylarger dimensions. After placing of a panel 5 with fabric 1 in position,it is held in place by means of a plate or metal sheet.

While pneumatic cylinders have been mentioned as the means for switchingthe different parts, there is, of course, nothing to prevent otherswitching mechanisms from being applied, even though pneumatic cylindersare to be preferred.

The present invention is, naturally, not restricted to the embodimentdescribed in the foregoing, many modifications being conceivable withoutdeparting from the spirit and scope of the inventive concept as definedin the appended claims.

We claim:
 1. An apparatus for forming corners in a covering for a panelcomprising means for positioning the covering to surround the panel andto extend from edges thereoff means for forming at least two firstinward folds from two opposing edges of the covering and for causing thefirst inward folds to overlap one another; means for forming secondinward folds from the opposing edges, the second inward folds beinglocated inside the overlapping, first inward folds; a corner support forforming a corner by inward or final folding of the second inward foldabout the corner support; an adjustable stirrup for aiding inwardfolding of the second inward fold about the corner support while leavingexposed an adhesive application surface on the second inward fold; meansfor applying an adhesive to the adhesive application surface; a firstfolder for inward folding of a first one of the first inward folds; anda second folder for inward folding of a second one of the first inwardfolds after application of adhesive on the adhesive application surface.2. The apparatus as claimed in claim 1 wherein the corner supportcomprises a rod, and a needle pivotally and displaceably disposed on therod so that in a supporting position of the needle in the corner, theneedle extends along the corner.
 3. The apparatus as claimed in claim 2,wherein the corner support further comprises a needle support, andwherein the needle is longer than the corner so as to extend past thecorner for cooperation with the needle support to retain the needle in adesired position in the corner.
 4. The apparatus as claimed in claim 3,wherein the needle support is displaceable to and from the positionsupporting the needle.
 5. The apparatus as claimed in claim 1, whereinthe stirrup is a wire stirrup and is switchable past the corner, forinward folding of the second inward fold about the corner support, andback to its starting position in a path outside the adhesive applicationsurface.
 6. The apparatus as claimed in claim 5, further comprising acorner-forming plate, and wherein the wire stirrup is disposed tocooperate with the corner-forming plate to urge the second inward foldagainst the corner support.
 7. The apparatus as claimed in claim 5,wherein the wire stirrup is insertable past the corner and is pivotalout therefrom for returning to its starting position.
 8. The apparatusas claimed in claim 1, further comprising displaceable shears disposedin each corner for cutting the covering and forming the inward folds orflaps.
 9. The apparatus as claimed in claim 6 wherein the wire stirrupis insertable past the corner and is pivotal out therefrom for returningto its starting position.
 10. The apparatus as claimed in any one ofclaim 1-8 or 9, further comprising a piston and cylinder assemblyinterconnecting the corner support and the stirrup to provide desiredswitching thereof.